As I can see on the web, Teclast uses cheap batteries in their tablets and laptops.
My Teclast F6 Plus is only 1 year old and the battery is at 35% of its original capacity. Discharge/full charge did nothing. I also disconnected the battery for 10 minutes. No improvement.
Whatever I tried, nothing worked. I have to buy another battery, no choice.
Damn Chineses !!!! Always cutting the corners somewhere to sell cheaper.